Nervous Systems Ch.48

nerve net

arrangement of neurons in simple animals

central nervous system

consists of the spinal cord brain and transmits signals from the PNS to the brain and back

peripheral nervous system

nerves that stretch from spinal cord and allow for the perseption of external stimuli

sensory neurons

transmit information from sensors to central nervous system

interneurons

integrate information in central nervous system

motor neurons

transmit output from the CNS to effector cells

effector cells

trigger response in body

neuron parts

dendrites, cell body, nucleus, axon hillock, axon, nodes of ranvier, schwann cells, myelin sheath, synapses, synaptic terminals

presynaptic neuron

neuron sending on the signal

postsynaptic neuron

neuron receiving signal

glial cells

cell in nervous system that supports the structure of the nervous system

astrocytes

provide structure for extracellular ion concentrations and neurotransmitters

blood brain barrier

cells that surround blood vessels in brain to help regulate what goes in and out

membrane potential

voltage of each cell

resting potential

voltage of a neuron transmitting signals

stretch ion channels

gated ion channels that open and close depending on the physical state their surroundings

ligand ion channels

gated ion channels that open and close depending on a specific binded ligand

voltage ion channels

gated ion channels that open and close depending on the surrounding voltage

hyperpolarization

increase in magnitude of membrane potential

depolarization

reduction in magnitude of membrane potential

graded potential

localized temporary change in cell’s membrane potential

threshold

membrane voltage required to generate an action potential

action potential

depolarization that generates and send an elextric signal down the axon of a neuron

what makes action potential more efficient

size of axon and myelination

synaptic cleft

space between neurons into which neurotransmitters are released and bind to the postsynaptic neuron causing the next electric impulse to be generated

excitatory postsynaptic potential

voltage in neuron that makes it fire

inhibitory postsynaptic potential

voltage in neuron that makes it enter an inhibitory state preventing it from firing

temporal summation

multiple excitetory postsynaptic potentials received by the same synapse on a neuron in quick succession

spatial summation

multiple excitetory post-synaptic potentials recieved by different synapses on the same neuron

indirect synaptic transmission

neurotransmitter binds to a receptor not connected to a channel activating a signal transduction pathway

acetylcholine

excitetory neurotransmitter secreted in nervous system by vertebrate skeletal muscles (can be excitetory or inhibitory otherwise)

epinephrine/norepinephrine

secreted by nervous system and INJ can be both inhibitory and excitetory

dopamine

secreted by nervous system and is excitetory

serotonin

secreted by central nervous system and is inhibitory

GABA

secreted by nervous syetm and INJ and is inhibitory

Endorphins

secreted by central nervous system and is inhibitory

nitrous oxide

secreted by central nervous system and INJ and is excitetory

gray matter

surrounds the cortex

white matter

makes up the inner part of the cortex

somatic nervous system

in charge of voluntary movement and signal transfer

autonomic nervous system

in charge of involuntary movement and internal environment

parasympathetic nervous system

returns body to resting self-maintaining state (rest and digest)

sympathetic nervous system

activates fight or flight response

embryonic development regions

hindbrain, midbrain, forebrain

brainstem (parts)

medulla oblongata, pons, midbrain

medulla oblongata

life functions like breathing, heartrate, vomiting

pons

life functions like breathing

midbrain

vision and hearing processes necessary for homeostasis

reticular formation

network of neurons that regulate sleep and arousal

cerebellum

control of motor and perceptual functions

diencephalons

epithalamus, thalamus, hypothalamus

epithalamus

cerebrospinal fluid production from blood

thalamus

sensory information sorting

hypothalamus

maintaining homeostasis

circadian rhythms

biological clock compotent in charge of sleep

cerebral hemispheres

basal nuclei and white matter covered by a layer of grey matter, sensory information is analyzed and responses are made

left hemisphere

language, math, logic, serial sequence processing

right hemisphere

emotion processing, thinking, pattern recognition

corpus callosum

tissue connecting right and left hemisphere

limbic system

system of structures around brainstem in charge of emotions/feelings in charge of survival